Computational and Photoelectrochemical Study of Hydrogenated Bismuth Vanadate
Computational and Photoelectrochemical Study of Hydrogenated Bismuth Vanadate
复制标题
氢化钒酸铋的计算和光电化学研究
DOI：
10.1021/jp401972h
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发表时间：
2013-05-30
影响因子：
3.7
通讯作者：
Li, Yat
中科院分区：
文献类型：
--
作者：
Wang, Gongming;Ling, Yichuan;Li, Yat
我们证明氢化作为一种简便的方法，以显着提高性能的BiVO 4薄膜的光电化学水氧化。通过在氢气气氛中在200 ° C和400 °C之间的升高的温度下对BiVO 4膜进行退火来对BiVO 4膜进行氢化。氢气可以还原BiVO 4以形成氧空位以及氢杂质。密度泛函理论计算表明，氧空位和氢杂质都是BiVO 4的浅施主，形成能较低。这些缺陷可以在不引入深陷阱态的情况下提高BiVO 4的施主密度。电化学阻抗测试表明，氢化后BiVO 4薄膜的施主密度显著提高。氢处理的BiVO 4（H-BiVO 4）光阳极实现了最大的光电流密度为3.5 mA/cm 2，在1.0 V时，Ag/AgCl，这是1个数量级高于空气退火的BiVO 4在相同的电位。增强的光活性归因于供体密度的增加。
We demonstrate hydrogenation as a facile method to significantly enhance the performance of BiVO4 films for photoelectrochemical water oxidation. Hydrogenation was performed for BiVO4 films by annealing them in hydrogen atmosphere at elevated temperatures between 200 and 400 °C. Hydrogen gas can reduce BiVO4 to form oxygen vacancies as well as hydrogen impurities. DFT calculation predicted that both oxygen vacancies and hydrogen impurities are shallow donors for BiVO4 with low formation energies. These defects could increase the donor densities of BiVO4 without introducing deep trap states. Electrochemical impedance measurements showed that the donor densities of BiVO4 films were significantly enhanced upon hydrogenation. Hydrogen-treated BiVO4 (H-BiVO4) photoanodes achieved a maximum photocurrent density of 3.5 mA/cm2 at 1.0 V vs Ag/AgCl, which is 1 order of magnitude higher than that of air-annealed BiVO4 obtained at the same potential. The enhanced photoactivities were attributed to increased donor den...